In recent years, ozonated water has been used for various purposes, such as the sterilization of food and the deodorization of malodorous gas. Furthermore, many findings about the ozonated water have been reported in the medical and nursing-care fields. The semiconductor production also needs the ozonated water, which exhibits characteristic ozone oxidation to hyperfine structures.
The ozonated water is typically generated through direct electrolysis (e.g., refer to Patent Document 1). In the direct electrolysis, feed water is brought into direct contact with the electrolytic surface of catalytic electrode, which includes a cation exchange membrane, and an anode and a cathode in pressure contact with the cation exchange membrane on the respective surfaces, to be electrolyzed into ozonated water.
In a typical procedure for the pressure contact between the anode or cathode and the cation exchange membrane, for example, as illustrated in FIGS. 8A and 8B, a pushing screw 41 is tightened in a housing 11 stacked on a grating 34 disposed on an anode 32 to urge the anode 32 against a cation exchange membrane 31. In FIG. 8, the housing 11 has a feed-water supplying path 5 and an ozonated-water discharging path 6 for discharging the resulting ozonated water, which penetrate through the housing 11 to the cation exchange membrane 31. Feed water supplied through the feed-water supplying path 5 comes into contact with the anode 32 and the cation exchange membrane 31, and the resulting ozonated water is then discharged through the ozonated-water discharging path 6. It is noted that a cathode (not shown) is disposed below the cation exchange membrane 31.